Remote valve control and position indicator system



3 Sheets-Sheet l IPEMOTf (WAIT/ML SYSTEM V/IL VE POG/ T/ON lND/CHTUIPS(9 (D (D Q) Q) 4 5 Q) Q) G) (D Q) E E E E E E E E E E J. A. DbNDERO ETALREMOTE VALVE CONTROL AND POSITION INDICATOR SYSTEM maps MID/carol? 11HEMP.

S 5 0 1 10 R r7 M 0 0! v R T4 0 5 N T EM. mu m m I my Ew 1 m7 9 R. d M RJ Em E M 0 Em m. m m 10 f i a m m n w m mm mn w z L R m 6 I I 6 m a m jm m r 0 6 m m/ X 4 Ed 86 a M g 1 w RH w M DOOM U 1 mm H m R ooowm m 2 m.im m Z i wk f M a l.|.|.lI.l L 5 n May 25, 1954 Filed June 22, 1949 May25, 1954 Filed June 22, 1949 J- A. DONDERO ET AL REMOTE VALVE CONTROLAND POSITION INDICATOR SYSTEM 3 Sheets-Sheet 3 DROP M-AMLMA flTTORNEYPatented May 25, 1954 REMOTE VALVE CONTROL AND POSITION INDICATOR SYSTEMJohn A. Dondero and HerbertN Fochs, New York, N. Y.

Application June 22, 1949,-Seria1 No 100,594:

6 Claims. 1 The present invention relates to an electriccircult onsystem and parts therefor and more particularly to an electric circuitfor controlling from a central location the operation of one or moreremotely located pieces of equipment.

Since the present invention is highly useful in.controlling steamheating systems utilized in" large housing projects and the like, whichutilize a central heating plant for supplying heat. to a number ofdiiferent apartment units or groups, it will for convenience ofillustration and description. bedescribed chiefly in connection withsuch usage. It isto be understood, however, that its field of usefulnessis not l mited to controlof a heating system; it may be used withvarious industrial plants, chemical plants, factories, dwellings,housing projects, signal and signalcontrol installations, and the like.

In housing projects such as referred to above the central heating plantisconnected by steam supply and condensate return pipes with various'different. apartment units to be heated. For example, it may bconnectedv with as many as thirty or forty different apartment units.At.

each difierent apartment unit or group steam supplyand condensate returnpipes for. that unit come to a local'heating control room, in which arelocated vacuum and condensate. pumps together with their driving motors,steam control valve together with a motor or other means for.electrically operating it,. a selector for measuriirg, outsidetemperature, a heat balancer. for measuring indoor temperature, controlpanel, traps,etc.

Under previous systems such as the above the heating of." each of thirtyor forty difierent apartment units has been controlled at each of' thecorresponding thirty or forty different local control rooms. There hasbeen no centralized control of all the different localized control roomsfrom a single point. As a result an operator has had to visit each ofthe local control rooms to start the. system, bring it up to anoperating level, periodically supervise the system and controls duringlocalized automatic operation, and to cut off the equipment in theparticular local heating control room at the end of the heatingday.Usually one operator has to take car of five, six or more differentlocal control rooms; with thirty or forty different local control roomsthis means that six, eight or more operators are required in order tocontinually supervise the local control rooms and the heatingsystemrequirements.

For example, during the heating season the vacuum pumps for a givenapartment group must generally be turned on by an operator at 5 a. m.

in each local controlroom'; At 6 a. m. the local steam valve must beopenedonly a limited'amount and remain: so for'a period of time. Whilevacuum pumps and steam valves can be turned on.

by'individual time; clocks for each different iece Of equipmentthis isnot. preferred since it lacks supervision by an operator and since itmay be desired. to vary these times in earlier or later directions inaccordanc with existing Weather conditions, which would require theoperator resetting and adjusting the equipmentand the varioustimeclocks.-

Aft'er anlelapsed time the. steam valve is opened a further amount,manually only, beyond the initial position. These. two steps of. openingthe valve are. important since: they reduce or eliminate steam. line.noises, impose a gradual load on the boilers and insure. that thebuildings are properly heated. during th initial heating. up period.This procedure generally requires from one. and one-half to two andone-half hours, varying with outside temperatures;

After the steam valvehas been opened thedesired full amount, at theendof'the one and onehalf to two and one-half hour period, the operatorthen may place the system in an automatic local control condition, minoradjustments then being requiredfrom time to time throughout" the heatingday to maintain normal building temperatures. During the'remain'der ofthe heating day the' operator periodically checks the pump" operations,temperatures, et. cetera, at each of the local control rooms under Atthe end of the'heating day the operator must shut off the steam valveand pumps, either by hand or by means of a manually preset time clockcontrol this secures the system for the night. 'Ifhe'above cycle must berepeated for each heatin'g'day.

It can be readily appreciated that the above procedure is time consumingand expensive, as wellas ineilici'ent at best; If operators are notprompt to start the pumps and open the steam control valves and tocorrect for changes in temperature or for wind conditions, there arecomplaints from tenants. In addition, where the operator doesznot do hisjob most efficiently there results great heat wastage and. consequentfuel consumption and tuellcosts.

The present invention aims to overcome the above and. other difiicultiesor disadvantages by providing a new and improved electric circuit and.controlling and; indicating means by which any" number of: differentapartment units or groupssm'ay be accurately and readily controlled froma single central locationby a single operator. and improved temperatureindicating and alarm system which accurately shovls'at the singlecentral locationthe' steam temperature at any dohis supervision.

A further aim is the provision of a new sired remote point of theheating system. The invention further contemplates the provision of asimplified electric circuit having minimum wiring which may be readilyapplied to existing housing projects or the like.

An object of the present invention is to provide a new and improvedcontrollin and indicating circuit or device.

Another object of the invention is to provide a new and improvedcontrolling circuit or system which employs minimum electrical wiring.

Another object is to provide a new and improved method of controllingthe operation of an electric motor or other device from a remotelocation.

Another object of the invention is to provide a new and improved andpreferably combined temperature indicating and temperature alarm device.

Another object of the invention is to provide a new and improvedcontrolling and indicating circuit for a plurality of remotely locatedunits, which may be operated by a single operator from a singlelocation.

A further object of the invention is to provide a new and improvedcontrolling and indicating circuit or device which may be readilyapplied to existing housing projects or the like.

A further object of the invention is to provide a control circuit ordevice which embodies new and improved means for accurately indicatingthe position of a remotely located member such as a fiuid-controllingValve.

A still further object of the invention is to provide positivesynchronization between control or controlling point to a local orcontrolled location.

Other and further objects of the invention will be obvious upon anunderstanding of the illustrative embodiment about to be described, orwill be indicated in the appended claims, and various advantages notreferred to herein will occur to one skilled in the art upon employmentof the invention in practice.

A preferred embodiment of the invention has been chosen for purposes ofillustration and description and is shown in the accompanying drawings,forming a part of the specification, wherein:

Fig. l is a more or less diagrammatic view showing a form of the presentinvention;

Fig. 2 is a wiring diagram for the device illustrated in Fig. 1 showingthe parts in greater detail;

Fig. 3 is a wiring diagram showing a temperature indicating andtemperature alarm portion of the present device or system;

Fig. 4 is a chart illustratin the status of the apparatus or systemunder various operating conditions;

Fig. 5 is a wiring diagram illustrating another form of combinedtemperature indicating and temperature alarm circuit; and

Figs. 6a and 6b are wiring diagrams showing another form of theinvention.

GENERAL DESCRIPTION Referring more particularly to Fig. 1 there is showna master panel I located at some central position, preferably at thesteam plant which generates steam supplied to the various outlyingapartment units or groups. At the right side of the master control panelis shown a plurality of multiple position selector switches 2, oneselector switch corresponding to each local control room of eachapartment unit or group; as a matter of convenience in illustration anddescription fifteen diiierent selector switches are shown. Each selectorswitch is connected by a separate pair of control conductors, 5a and 5b,with a control relay panel l of a local heating control room 8. Each ofthe selector switches has operatively connected with it a correspondingsteam valve position indicator; thus when a selector switch on themaster control panel is used to control a steam valve at an outlyingcontrol room the position of the particular remote steam valve isclearly indicated to the central operator.

The selector switches 2 may have any number of positions, correspondingto the requirements of the particular equipment to be controlled in alocal heating control room. The selector switches may be of rotary, cam,key or any other construction whereby incoming feeder voltages andcurrents may be switched in various combinations to the outgoing controlwires 5a, 5b which join the master panel I with the control relay panell in a local control room 8. By utilizing the selector switch 2 tochange and vary these voltages and currents, corresponding relaypositions are obtained at the local control room. The particular relaypositions thus obtained make and break various electrical connectionsand thereby control the operation of electrical parts and connectedequipment. Thus by means of a selector switch corresponding to eachlocal control room the entire heating system may be controlled from themaster panel by a single operator; each local control room is controlledindependently of any other. This is a highly desirable feature sinceapartment units or groups controlled through clifierent remote localcontrol rooms may be exposed to widely varying conditions of wind, andsun, which greatly affect the heating requirements therein. Contacts arealso provided on each of the selector switches which through timingmotors serve to indicate on the master panel the position of the steamvalve at a particular local station.

With the present embodiment described herein each selector switch hasseven different positions, as shown in the chart of Fig. 4. There may,of course, be a greater or lesser number of positions, depending uponthe particular equipment to be controlled.

t the opposite side of the master panel are shown temperatureindicating-temperature alarm switches it, a temperature indicator ll,alarm relays it and the annunciator drops M which are actuated when. thetemperature alarm is actuated. There is shown a separate temperature andalarm switch for each of the various outlying local control roomsfifteen being shown for purposes of illustration and description. Eachtemperature indicating-alarm switch i0 is connected by a separate pairof conductors 16a, 16b with an alarm relay box ill of a local controlroom 8.

The center portion of the master panel I is shown broken away toindicate that it may be of any desired size. This center part may carryvarious panel equipment, clocks, indicating lights. et cetera, withwhich the present invention is not concerned.

The equipment located at a single local control room 3 is indicateddiagrammatically in Fig. 1. Only one remote local control room is shownand will be described as the others are similar in construction andoperation, hence a description of one will sufilce for all.

switch 2 for the remote control room 8 serves toact-uate the relays ofthe control relay panel I and of the Vacuum pump relay panel as willbe-more fully brought out hereinafter, to thereby start and selectivelycontrol and stop the-operation of the vacuum pump drive motor as.

In addition, selectively setting a selector switch 2 at the master panelI also serves to actuate various relays at the control relay panel 1 anda heating control panel 22 to operate a particular motor or actuator 28which moves the steam valve 29.

When a particular selector switch 2 is used during an initial warm upperiod to selectively control steam valve settings, a correspondingvalve position indicator 4 is automatically cut in to visibly indicateon the master panel, either exactly or approximately, a steam valve setng. The valve position indicator 4 may come one or more motors ltd,I82), [be geared or co..- ected by common shaft 26 (Fig. 2) to a commonpcin' preferably three diI fere-nt motors utili d, one (E80) to controloperation of the indicating pointer during slow open-- ing rate of steamvalve 28, one (lab) to control movement of the pointer at fast openingrate of the'stearn valve one (13a) to move the pointer when the steamvalve 23 is moved toward closed position, the number of valve positionindicators or motors depending upon the requirements for the selectorand the operating needs of the particular installation. These motors arepreferably of the synchronous type and measure the time that the valveis opening slowly, opening rapidly, or closing; the face of theindicator is, however, preferably calibrated in accordance with thevalve itself to show the amount that the valve is open rather than beingcalibrated in units of time. The timing indicators may not always be inexact synchronisin with the valve position, but may be onlyapproximately so. For example, a valve may be assumed to open full intwo minutes under fast opening or ten minutes under slow opening. Inthese instances the indicator turning through a revolution acts as a twominute hand in one case and as a ten minute hand in the other. The valveposition indicator 4' is used only during periods while the master panelI has control and is not used during periods when the selector switch 2is set to give automatic control or" the steam valve position toequipment at alocal control room.

After being brought through a heating up period by exercising controlfrom the master panel I the local heating control room may be set on daycontrol or compensated control,

in each of which positions the particular local control room is givenlocal command and there exists a localized automatic control at theparticular remote control room.

The temperature indicating and temperature alarm switches i l shown atthe lower left portion of the master panel l are each connected with thetemperature'indicator H, with an alarm bell or buzzer t2, and with aseparate annunciator- 6 drop l4. They are also connected by the pair ofconductors lfia, 161) with the alarm relay box I! in the remote localcontrol room. This alarm relay box I I is shown connected by a pair ofcon-- ductors 30 with a resistance thermometer 3| normal day operationto a compensated operation. This remote temperature indicating portionis highly desirable in obtaining the highest possible efilciency of theheating system. In addition, the temperature alarm system combined withthe temperature indicating system over thesame connecting wires, givesan indication to the central operator of mechanical or electricalfailures ofv equipment contained in the remote control room.

There will now be described in greater detail the construction andoperation of the circuits and their parts.

In one embodiment of the invention alternating current of about volts issupplied through conductors to a direct current converter or rectillerand to a valve position indicator, the output side of the converterconnecting with a multiple contact selector switch. The direct cur--rent converter or rectifier connected to the alternating current supplyprovides: two direct current voltages, preferably of about 69 voltspositive and 120 volts positive. Other suitable voltage values,frequencies, whether superimposed or not, may be utilized, as will behereinafter brought out, those herein referred to being examples ofthose which may be employed.

The local control panel controls the operation of the steam valves andvacuum pump at local control station, through the relays 2-2, til, it(Fig. 2). These relays may be controlled either remotely from selectorswitch 2 at the master panel or directly in the local heating controlroom. As previously brought out, each. selector switch is a multiplecontact switch, which in the present embodiment has six different onpositions and one oil? position. A rotary type switch is a compact andefiicient one which gives good results. The output of the positionselector switch is shown coupled to the particular local control room bytwo conducting Wires 5a, lib. Instead -of utilizing two conductors to,5b as shown, one

of these conductors may be a ground return, thereby requiring only asingle wire. The input sides of the contacts or the selector switchesare coupled with the 60 volt direct current and 120 volt direct surrentsupply lines to thereby provide for different voltage conditions acrossthe output conducting wires as indicated in the chart of Fig. 4.

Vacuum pump relay panel number of motors, or other devices as the case 7may be. The primary winding 13w of the transformer I3 is shown connectedto a 208 volt A. C. supply producing across the output of the secondarywinding 13b a voltage of about 24 volts. The winding Ia. of the relay 5|is connected in series with the secondary of the transformer and theinput terminals 12, M. When the circuit is closed across the terminalsl2, 14 by contact 42' of the control relay panel I the voltage in thewinding 13b is applied across the coil 5Ia of the relay and energizesthe coil actuating the contacts 52, 53. The details of the circuitswhereby the above devices are actuated from a selector switch 2 will befurther brought out hereinafter.

H eating panel The heating panel 2'! may be of generally knownconstruction and includes an automatic heat regulator 54, indicatedgenerally, relays 58, 59 and a transformer 55. The automatic heatregulator automatically adjusts the steam supplied in response to theheat requirements of the building being heated; there are two types ofautomatic control, day control and compensated control. Automatic daycontrol is used when weather conditions are normal and automaticcompensated control i used when there are unusual weather conditions ofwind, sun, et cetera. The automatic regulator may be shifted fromcompensated to day control by the relay 58 which has two contacts 58,and 58". When contact 58 is closed the automatic heat regulator is inclay automatic control and when contact 58" is closed the regulator isin compensated automatic control. The coil 58a is shown connected inseries with a voltage source I05 and output terminals. 93", S9".

The relay 59 with split windings 59a, 59b and two contacts 59', 59",controls the direction of movement of the valve actuator or motor 28when the automatic heat regulator is in charge and controlling theheating system. The winding of the relay 59 is divided into two parts bythe terminal I3! connecting the center of the Winding with the automaticheat regulator M.

The ends of these windings are connected to the automatic regulatorthrough the terminals I30, I32. The winding 59c actuates contact 59' toclose the steam valve and winding 59b actuates contact 59" to open thesteam valve. The contact 59' is connected between terminal it and 95".Contact 55 is connected [between terminals 95 and 9B. The terminals 16"and 90 are connected to the opposite ends of the two windings 28A, 2813.The adjacent ends are connected at terminal I34 and to the secondarywinding 55?) of the transformer 55 through terterminal I35. A limitswitch may be inserted as shown between the coil 28a and terminal '16"to open the circuit when the valve is closed.

The winding 55b of the transformer 55 i connected across the terminalsI35, 11'. When the automatic regulator is connected, the circuit betweenterminals TI" and 95" is closed by contact 42 of the relay controlpanel. The primary winding 55a of the transformer is connected to a 120volt A. C. source of voltage. The voltage in the secondary winding isplaced across either winding 28a. or 2th, depending on whether contact53' is closed or 59 is closed. The coil 59a is energized when theopening of the steam valve is to be reduced and the Winding 59b isenergized when the steam valve opening is tobe increased. The circuitdetails whereby the above referred to heating panel devices are ac-' =5posite switch poles 3B and 8 tuated from a selector switch 2 which willbe further described hereinafter.

Heating control relay panel and valve position indicators The conductors5a, 5b are shown connected to the relay coils of the control relay panel1 through a triple pole, double throw switch 35, the conductors beingconnected to input poles in, 38 respectively. In this embodiment thecoils of the relays 42, 43, M are connected in series between theopposite poles :39 and 4!, which poles are connected with the oppositepoles 31, 38 respectively, when the switch 35 is in the remote positionindicated in Fig. 2. The relay coil 43 is bypassed by a rectifier M3 andresistor 49 in series. A rectifier Bil is connected in series with thecoil relay 43 so as to force the current through the bypass circuit whenthe pole 31 has a positive potential with respect to pole 38. i elay Mmay operate when 120 volts, for example, are applied across the poles itand ll. Relays 42 and it may operate when 60 volts, for example, areapplied to poles it and il. The remaining opare connected to thecontacts of the relays 12 and The coil of relay 32 actuates the contacts42 and 62''. On the positioning of the rotary switch 2 from the neutralor off position a positive 60 volts is applied over the lines 5a, 52)through the switch contacts 37, 38; the coil relay d2 closes the contactd2 opens the normally closed contact 52". The contact 42' is connectedto the relay 5| in the vacuum pump relay panel and closes the circuit sothat the voltage from the transformer connected to the electrical systemof the building is applied across the coil of relay 51, closing thecontacts of the vacuum pump. The closing of contacts 52 and 53 startsthe vacuum pump motor to operate the vacuum pump to and exhaust air,gases, et cetera from the heating system.

When the contact 42" is in closed position there exists a closed circuitthrough the closing winding 23a of the motor 28, the limit switch 80,and the transformer so that the voltage is applied across the winding toactuate the valve motor 728 to thereby close the valve 29. On excitationof winding 28?) the motor opens the valve 29.

The normally open contact er of the relay 44 is closed on theenergization of the coil of relay 6-! when 120 volt positive potentialis applied to the terminal 40.

This completes the circuit in the heating panel so that the winding 2%is excited by current from the secondary of the transformer 55 actuatingthe valve motor to open the valve 29 which is connected thereto. Theamount that the valve 29 is opened or closed. is indicated by thecorresponding valve position indicator 4 on the master control panel Iat the central control room.

Each of the valve position indicators is shown driven by one of threedifferent motors I8a, I8b or I controlled by three contacts BI, 81 or9|. respectively. When contact 85 is closed the closing timing motorI30: is energized by the volt source across terminals 66a, 55b and showsthe closing of the valve 2'9; closing contact 81 similarly energizes thefast opening motor I81) and shows the opening of the valve 29, andcontact 9I energizes the slow opening motor iBc to show slow opening ofthe valve 29. The contacts 8|, 8? and 9! are on the position selectorswitch 2 at positions 2, 4 and 5 (Fig. 4) corresponding to the contactsclosing the valve, opening the valve rapidly, and opening the valveslowly.

The coil of relay S3 actuates the contact 53 when a negative voltage ofeither 60 volts or 120 volts is applied to terminal 31. With contact 43'closed the valve motor is placed in control or the automatic regulatorand relay '59.

The coil of relay t3 also actuates contact til when a,negative 120 voltsis applied to terminal 31. l The coil of relay i l simultaneouslyactuates contact 44" to complete the external circuit across theterminals iii!" and $8. This shifts the operation of the automaticregulator 5d from compensated automatic control to day automaticcontrol. Contact 93" is also opened at this time to prevent undesiredcircuit closing between terminals 11' and 9B.

The operation of the present device or apparatus will now be describedin connection with various conditions set up by selective positioning ofthe selector switches 2.

Position 1 As previously stated, each switch 2, which may be of therotary type, has seven contacts; one contact is an off or inoperativeposition and the other six contacts are operative positions forcontrolling the local heating systems. In Eig. 4 the chart showsposition 1 as the on position. The vacuum pumps are shut off and thesteam valve is shut oil.

In Fig. 2 the various switch positions are indicated by vertical arrowspointing toward the contacts that are closed when the switch is set atthat particular position. The switch contacts connect the D. C. voltagelines 65b and. 650 with the control lines 5a, 5b and also connect thevalve position indicator motors across 120 volt A. C. supply lines 860.and dill). In position 1 the D. C. lines slid, tllb and are notconnected to the connecting control lines lib so that no voltage isapplied to the input terminals 38 of the switch at the control relaypanel. Therefore there is no voltage applied to the input terminals 31,t3 and the relay coils d2, it, M. With no voltage across these coils therelay contacts are not actuated and are in their normal position.Contact 32 is open and the circuit is open from the terminal relay panelthrough to the terminal l2, through the secondary of the transformer it,the relay coil 5!, the terminal post 5 3 back to the terminal post i i.No current is supplied from the secondary winding 73b of the transformeris to the relay coil 5!. Under these conditions the contacts 52 and 53of the relay iii are in their normal open position so that the vacuumpump motors do not operate. At the control relay panel the contact 42"is closed completing the circuit from terminal iii through the contact32", through the terminal post 35 of the switch through the switch blade3%, from the terminal post 35" along the line iii to the output terminalpost H of the control relay panel along line ii to terminal ll of theheating panel thence through the secondary of the transformer at theheating panel, through the limit switch at and the winding 28:: of thetwo winding series motor 28 to the terminal "it" through the wire it toth terminal iii. The closing of this circuit applies the voltage in thesecondary iifib to the winding 28a of the motor 23 and turns the motorto move the steam valve toward closed position; when the valve is fullyclosed the circuit is opened post it on the control 10 by limit switch80. This condition is a normal condition for the position 1 since it isan ofi position or closed down condition of the heating system. Thecontacts 52, 43, 43", 44' and 44" are in the open position and therespective circuits are open.

Position 2 When the selector switch is set at position 2 the electricalcircuit arrangement of the local control relay panel and heating panelare the same as in the position 1. The voltages on the lines 55b, 65care not applied to the output terminals tic, all) or lines to, 5?) sincethere are no contacts to connect them. This position is used to shut theheating system down. The limit switch iii! is closed since the steamvalve 29 is still open. The position of the steam valve is indicated bythe valve position indicator. This pointer of this indicator is actuatedby the closing of the contact til when the switch is placed in position2. This is the only contact of the selector switch that is closed whenit is placed in this position. The current from the 120 volt A. C.supply then passes through the completed circuit from the terminal 66athrough the timing motor i811, the closed contact 8| to the terminal6617.

Position 3 In position 3 of the selector switch the vacuum pump motors29 are started preparatory to admitting the steam, and the steam valveclosing circuit is opened. The contacts 82, 83 of the position selectorswitch are closed completing the circuit from the input terminal 86a tothe input terminal 850: to apply a positive volt to the control relaypanel. The circuit is completed from terminal lite on the 60 volt D. C.line b along line 86 through the contact $2 to the output terminal 51a;thence along the control line 50a to the input terminal 31 of the switch35, through the switch blade 3?, the terminal to to the coil of therelay (i2, thence through the rectifier 48 and the resistor 43 and thecoil of relay id to the terminal 4|; thence through the switch blade38', the output terminal 33 and the line 51; to the input terminal t'ib;and finally through the closed contact 83 along line 85" to the inputterminal 8511 connected to the ground line 65a.

The voltage across the coil of relay 62 opens the contact 42" and closesthe contact 42'. The closing of contact 42' closes the vacuum pump relaycircuit from terminal in through the contact 42, to the terminal ll,through line tea to the terminal Hi, through the coil of the relay 5|,the secondary 13b of the transformer it to the terminal 12 through theline 2 522 to the terminal 10.

The current produced by the voltage in secondary winding 73?) passesthrough the coil of relay 5| to close the contacts 52, 53 of the vacuumpump motor to start the vacuum pump running.

With the opening of the contact 62" the circuit is broken from theterminal iii through line 75 to the terminal 36 of the switch 3-5, theswitch blade .36, the terminal 36" through line is to the terminal i1,thence through the connecting line ll, the terminal 1'!" to thesecondary winding 55b from the terminal I35 through the winding 28a ofthe motor 28 and the limit switch 8%), to the terminal Hi back toterminal iii and the winding 28a cannot be excited by current from thesecondary The valve motor will. remain in the position that it is set atwhen the selector switch is on position 3. The other relay contacts 43',43", 4 and M" remain open. Contact is" i of the steam valve.

11 is closed but does not complete a circuit since contact -14 is stillopen.

Position 4 In the fourth or fast opening position of the selector switchthe contacts 91, 98, 89 are closed. Contact 8:! connects the fastopening indicator motor to the output terminals 66a, 66b and starts thevalve motor 28 running.

Upon closing of the contacts 88, 89 the circuit is completed from theterminal 91a on the 120 volt line 650, through the contact 85 to theterminal 61a, control line So to the terminal 3?, switch blade 3?,terminal 49, coil of relay 22, rectifier 48, resistor 49, coil of relay44 to the terminal 4! thence through the switch blade 38', terminal 39.line 52), terminal 6711), contact 89 to terminal 85a on line 95a. Thisplaces 120 volts across the terminals l-ll, ll. Current flows throughthe circuit comprising the coil of relay 42, rectifier 48, resistor 49and coil of relay M. The contacts 42' and i2" remain in the sameposition as position 3. The coil of relay M is energized sufficiently toclose contact 44. The circuit is completed from terminal 90 throughcontacts M and 43", terminal 11, line H, to terminal ll to secondarywinding 55?), and the winding 23b of the motor 28 to the terminal 99"through line 90' back to terminal 99. The current then supplied by thevoltage of the secondary winding passes through the completed circuit toenergize winding 29b. The valve motor then starts to open the steamvalve 29 with the fast opening timer motor in synchronism with the valveopening to indicate the valve position. The remaining circuits are openrendering the relays inactive.

Position In position 5 the contacts 9|, 92, 93 are closed. This sets therelays and circuits for slow opening The closing of contact 9] completesthe circuit from the 120 volt A. C. supply terminal 65a through the slowopening timer motor, the closed contact 9| to the terminal 69b.

The circuit to the control relay panel 1 is completed from the inputterminal 95a through line 85', closed contact 92, line 61 to terminalBl'a, thence through the connecting control wire 5a to the inputterminal 31, across the switch blade 31' to the terminal 40, thenthrough the coil of relay 42, rectifier 59, coils of relay A3 and M,back to the terminal 4i, across the switch blade 38 to the terminal 38,then along the line 5b across the terminal 91b on the switch 2, alongline 61" in the switch and through the switch 93 to the terminal. 96a onthe positive 60 volt line. Under this circuit arrangement the terminal(all of the switch 35 is 60 volt negative with respect to terminal 33,or terminal 38 can be considered to be 60 volt positive with respect toterminal 31. This voltage across these terminals is the reverse of thatin the case of positions 2, 3 and 4. As a result the voltages across thecoils of the relays are opposite in polarity to the voltages across therelays when the selector switch 2 is in position 3 or 4.

Under these conditions the contact 52 is still retained closed andcontact 42" retained open, as when the switch is in position 3 or 4, thecontact 44' is open and the circuit is open between terminals 99" andll; that is, the circuit from terminal 11', line ll, terminal 11 throughthe contact W and 42 to terminal 90, line 95! to terminal 90" is open.

Voltage is applied to the opening winding 28b of the valve motor fromthe secondary winding 55b upon the closing of contact 13 by the relay43. This completes the circuit from terminal Ti" through line ll toterminal ll through contact 93 to terminal 95, along the line toterminal 95". The external circuit between terminals ill and 95" of theheating panel is then complete. At the heating panel 21 the circuit iscompleted along line 96 through contact 59", which is closed due totemperature differences, through the winding 28?) of the motor 28,through the secondary winding 55b of the transformer 55 to the terminalll. The circuit thus completed, the voltage on the secondary winding 55bis applied across the motor winding 28b and opens the valve 29 slowly.The contact 59" is under control of the relay 59 in the automaticregulator, which may intermittently open and close the contact 59" sothat the motor 28 and valve 29 are actuated for a short period and thenidle for a period. Thus the valve may be slowly opened by increments.

As previously brought out the automatic regulator has a day control anda compensated control. Normally the automatic regulator is undercompensated control since the contact 58" is closed when the circuitincluding the coil of relay 58 is open. In position 5 the relays 43 andit controlling this circuit do not close the contacts 3 and M. Thereforethe circuit portion between terminals 98", 99" is open. The control ofcontact 5%! is under compensated control as indicated in Fig. 4.

Position 6 In position 6 the circuit arrangements are the same exceptthat contact 9i is open, breaking the circuit connecting the slow timingmotor to the volt supply at terminals 66a, 662). In this position thevalve 29 is at a desired general posi tion but is subject to minorchanges, depending upon heat demands and weather conditions. Inoperating under these more or less steady conditions either contact 59'or 59" is closed by relay 59, opening or closing the steam valve, orboth may be opened, leaving the valve in a set position. This isoperation under compensated control.

Position 7 In position 7 the contacts Hi2 and H93 are closed completingthe circuit from the terminal 85a through the switch H92 along the linestil to terminal fila, thence along line So to terminal 3?, throughswitch blade 31 to terminal 49, from terminal ill through the coil ofrelay 42, rectifier 5t, coils of relay 43 and 44 back to the terminalll, thence through switch blade 38, terminal 38, along line 5?) toterminal 61b, from terminal Gib along line Bl" through the closedcontact N13 to the terminal 81a on the positive 120 volt line 950. Withthis circuit completed 120 volts is placed across the coils of therelays and has the same polarity as the voltages of positions 5 and 6.The contact A2 is closed and 42 is open. The contact 43 is closed,completing the circuit as previously described in connection withpositions 5 and 6. The circuit arrangement is the same as position 6,except that the coil of relay 43 and M closes the contacts 43 and M"respectively, completing the circuit from the terminal 98", line 98,terminal 98 through the closed contact 43", 44" to the terminal 99through the line 99' to the terminal 553 through the :battery or voltagesource I55, the coil of relay 58 to the terminal 98". With this circuitclosed or completed the battery or voltage source I05 energizes the coil58 which closes contact 58' and opens contact 58". This shifts theautomatic regulator from "compensated control to day control. Theopening and closing of contacts 59 and 5d" of the relay 59 will be thenunder the control of the day mechanism in the automatic regulator. Thevalve 29 will then be open or closed depending upon whether contact 59is closed or 59" is closed. If 59 is closed and 59" is open. the voltageof the secondary winding 55b will be applied across the coil 28a of themotor 23 to close the valve. If 59" is closed and 59' is open the valvemotor will be actuated to open the valve. If and 53" are both open thevalve will remain in position.

Disconnection from central control station The switch as at the localcontrol relay panel has three positions, a remote position, offposition, and a local position. In the remote position the switchconnects the control relay panel I to a position selector switch 2. Inthe above discussion of the various circuit arrangements the switch isin the remote position.

In the local position the switch blades 31, 38' are connected to theterminals 39, ii), M. This change does not alter the circuit arrangementof the relays 42, 43, 44, it only renders the relays inactive. Theycannot control the opening and closing of contacts 52, 42", ld'a, '22,43" and lt". contact with the terminal 39 of the switch 35 and completesthe circuit between terminals ll" and 95" on the heating panel to placethe automatic regulator in control of the adjustment of the steam valve.The external circuit is completed from terminal '17", line '11, terminal11, to terminal 35", through switch blade 36' to terminal .39. thence toterminal 95, line 95" to terminal 95".

In the off position the switch blades are not in contact with theterminals 36, 31, 38 of the remote position or terminals 39, 40, 4| ofthe local position. With the contact between the terminal 39 and theswitch blade 36' broken or open the automatic regulator no longercontrols the adjustment of the steam valve. This position would be usedwhen it is desired to leave the steam valve at some particular setting.

Alarm-temperature indicator During the initial heating up period andcontrol of the steam valve and vacuum pump motor from the central masterpanel location it is highly desirable to transmit to the central controllocation the steam temperature at or adjacent the local control room andalso to notify the central cperator or any failures or defects in thesystem. This may be achieved by the combined alarm and temperatureindicating system, shown at the left of the master panel and in Fig. 3,which is provided with a switch at the master panel to transfer thesystem from a temperature indicating condition to an alarm condition,and vice versa. Normally the switch Will be in the alarm conditionexcept when it is desired to ascertain the temperature at the remotelocation.

The alarm circuit is connected to the heating system and operating partsto indicate any failureor unusual or dangerous conditions that need Theswitch blade at is in terminal Hi5 of switch Hi? attention. The alarmtransmission circuit is shown in Fig. 3 with the coil of relay 68 andthe local alarm bell connected in parallel to the output of the alarmcircuit. The local alarm bell will sound in the particular local controlroom when any unusual conditions are indicated by the alarm circuit, andthe relay 69 actuates the contact 60' closing the alarm relay circuit tothe master control panel. The voltage source H4 which may be a one andone-half volt battery in series with a 20,000 ohm resistor H5 actuatesrelay El and contact 6!. This closes the circuit of the alarm buzzer atthe master control panel and the circuit of the visual annunciator dropto provide both an aural and visual notification of unusual andundesirable conditions at the remote location.

The connecting cable [8a, idle is also connected to the resistancethermometer 3! located in the heating system, and transmits to the termperature indicator changes in the resistance thermometer 3|. Thetemperature indicator is a meter which indicates resistance in terms oftemperature and any change in the resistance of the thermometer (it isshown by the temperature indicator.

Considering in detail the alarm and temperature indicating circuits atthe alarm relay and temperature indicating panel at the local contrclroom the alarm bell and indicating circuits are connected to an alarmcontact maker by lines lots, 16%. When the contact is closed in thecontact maker the circuit is completed through the lines illto, $527 tosound the bell 34 at the local control room. It also completes thecircuit through line 32a, relay til and line 32b. The relay is energizedby the voltage at the contact maker source closing the contact Eli. Thiscompletes a circuit through terminal I81, line Nib, through the switchknife I69 to the terminal H through the coil of the relay ti to theterminal H2 through the switch blade H3 terminal M3 to the line lfia,back to the terminal 538 at the alarm relay panel at the local controlroom to the voltage source H4 and thence through the resistor H5 back tothe closed contact fill. The voltage from the voltage source H4 is thenapplied across the relay GI to close the contacts 6| to thereby energizethe buzzer l2 and annunciator drop M. With the closin of the contact ii) the sound circuit is also completed through the resistancethermometer iii but this resistance does not affect the operation of therelay 6 i.

If a temperature reading is desired the switch H6 is disconnected fromterminals l H and 1 l2 and connected to terminal H6 and Hi. This thencompletes a circuit through resistance thermometer 3!, terminal it's,'lll'le iiib, terminal M9, switch blade its, terminal H5 through thetemperature indicator to terminal H7, through the switch blade iiii'terminal 5 l3, line Elia to termine-l i838 and thence to resistancethermometer 3%. With the closing of this switch, the circuit or" theresistance thermometer is then closed, and the temperature of theresistance 3! will be measured by the temperature indicator H. Thecircuit through the voltage source H4 and resistor l iii is incompletesince the contact fill is open. In the event that contact 68' closed toindicate an alarm while the switch Hi3 in con tact with the terminals 9ll, i it, the current supplied by :the voltage source lid throughresistor H5, closed contact Gil, terminal ml, 'l'me Nib, terminal 1.0.9,switch blade 493", terminal H6,

through the indicator ll, terminal H1, switch blade H3, terminal H3,line lfia, terminal [$8 to the voltage source lid is not large enough toproduce any injury to the temperature indicator meter.

The temperature indicating means serves as a guide when positions 1 and3 (Fig. 4) are used for manually operating a steam valve in incrementsfor setting and holding heating steam line temperatures. In. the otherpositions the temperature indicator is used for remote indication ofheating system steam input as required by weather and wind conditions;also for ascertaining proper or improper functioning of heating systemequipment.

In Fig. 5 there is shown another form of circuit arrangement for thealarm relay and resistance thermometer at the local control room. Thesingle contact of the relay lid is replaced by a double-acting contactwith contacts 60 and 69. The normal position of the armature of therelay til is in contact with 68". This places the resistance thermometer3! across the conductors of the cable it. When an alarm occurs the coilof relay til actuates the armature and it in contact with E6 closing thealarm circuit to the master control panel. Thus the resistancethermometer is isolated upon the sounding of an alarm.

Modified form of control system In Figs. 6a and 61; an arrangement offive relays ll, l2, 13, "M, E5 in the local control panel is shown inthe form of a four sided bridge, a relay in each side of the bridge andthe relay in the diagonal. The relays H2, E3, l4, in the sides haverec-triers l3, ll, l8, 79 respectively connected in se es with therelays. These rectifiers are connected so that when terminal All ispositive with respect to terminal it! the current passes through relays'52, ii and i l and when terminal ll; is negative with respect toterminal ll the current passes through relays 73, H, 15. Relays l2-"Hoperate when terminal til is at 60 volts positive potential and relays'illli operate when terminal Ml is at 60 volts negative potential. Therelays '52, ll, "I l operate when terminal 4!! is at 120 volts positivepotential and relays 13, "H, operate when terminal M is at 120 voltspositive potential.

The relay contacts are the same as the ones in Fig. 2. Contacts 42' and42 are operated by relay H. Contact 43 is operated by relay 12, contact43' by relay 13, contact 64 by relay 14, and contact 44" by relay 15. Ifdirect current voltages are applied to terminals 40, 4! in accordancewith the chart of Fig. 4 similar operational results will be attained.When the selector switch 2 is in position 1 or 2 there is no voltageapplied to the terminals 40, 4| and the coils of the relays are notenergized and the contacts are in' their normal position. When terminal40 is volts positive with respect to terminal 4| in position 3 of theselector switch the coils of relays 12, H are energized sulficiently toactuate contacts 42", 42', 43. In position 4 the selector switch appliesa positive 120 volts to terminal 40 and the coils of relays H, 12, 14are energized sufficiently to actuate contacts 42', 42", 43 and 44. Inpositions 5 and 6 the terminal 40 is a 60 volt negative with respect toterminal 4| energizing the coils of relays 13, H actuating contacts 42',42", 43'. In position '7 the selector switch 2 applies 120 voltsnegative to the terminals 40, 4! and relays 13, H, 15 are energized suf-16 ficiently to actuate contacts 42', 42", 43 and 44".

Additional contact combinations are available for system modificationsand variations by applying 60 or other cycle alternating voltages, tothe terminals 40, 4| of the circuit shown in Figs. 6a, 6b. In one ofthese modifications the 60 cycle, 60 volt alternating positive andnegative pulses may be applied to terminals 40, 41 to energize relaycoils ll, 12, 13 thereby actuating contacts 42, 42", 43, 43". All of therelays H, 12, 13, 14', 15 may be energized by volt positive and negativealternating voltage pulses being applied to terminals 40, 4|. Theapplication of 120 volt positive alternating current or pulses and 60volt negative alternating current or pulses to the terminals 40, 4|actuates relays H, 12, 13, I5 and the contacts 42', 42", J, 43", and44". The application of 60 volt positive alternating current or pulsesand 120 volt negative alternating current or pulses actuates the relaysH, 12, 13, I4 and contacts 42, 42", 43, 43', 44'. From this descriptionit is readily seen that with variations in the system circuits differentcontact combinations may be attained by the application of alternatingcurrent or pulses to the control system.

It will be clear that other suitable voltages may be utilized; forexample, voltages such as 12 and 24 or 120 and 240, whether alternatingor direct current, 60 cycles or otherwise, and that certain currents andfrequencies may be superimposed upon each other. The particularcombination utilized may depend upon the desires and operatingrequirements of a given installation.

It will be seen that the herein described remote control apparatus ordevice provides for control ling a heating system or the like from aremote location by using only four wires or conductors, two conductorstransmitting controlling signals and two conductors transmittingintelligence signals. Ground returns may be utilized where desired andsuitable. With the use of only two control conductors and three relaysat the control panel all the operating conditions at the heating systemmay be made or set up. Vacuum pumps may be turned on for any desiredlength of time before steam is admitted by the steam valve and they maybe kept running during closing or opening of the steam valve and alsoduring automatic control of the steam valve. The steam valve motor maybe actuated to open the steam valve quickly or slowly during the initialheating up period or it may be placed under the control of an automaticcircuit for adjustment of the valve in response to temperature changes.Control may be from the central station or may be readily turned over tothe particular local station. The device i relatively simple inconstruction and operation and is adapted to operate over long periodswith a minimum of attention or maintenance.

As various changes may be made in the form, construction and arrangementof the parts herein without departing from the spirit and scope of theinvention and without sacrificing any of its advantages, it is to beunderstood that all matter herein is to be interpreted as illustrativeand not in a limiting sense.

Having thus described our invention, we claim:

Apparatus for remotely controlling a vacuum pump motor and a steam valvemotor of a heating system from a central location comprising thecombination with a direct current source of voltage having first andsecond voltages of different values, of first, second and third relays,

a multiple contact switch at said central location for applying saidvoltages to said relays in differ-' ent combinations, a first rectifieroperatively beveen said first and said second relays and a secondrectifier and impedance in series around said first rectifi r and saidsecond relay for conducting current in an opposite sense to currentpassing through said first rectifier and said second relay, said firstrelay being adapted to start a vacuum pump motor of said heating systemon the application of a first voltage combination, said second relaybeing adapted to transfer control of said heating system to an automaticcontrol upon the application of a different voltage combination, andsaid third relay being adapted to control said steam valve motor uponapplication of another voltage combination and also to transfer controlof said heating system to automatic control.

2. A device of the class described for remotely controlling amotor-operated valve, comprising the combination of means connected withsaid valve operating motor for starting and stopping the motor,selectively settable means including a multiple contact switch having abank of contacts for actuating said starting and stopping means andconnected to said starting means by only two lines, and indicating meansactuable by another bank of contacts to synchronously turn said toindicate the approximate position of said valve, said indicating meansincluding a first electric motor for moving an indicator to showapproximate valve closing positions and a second electric motor formoving an indicator to show approximate valve slow opening positions,and a third electric motor for moving an indicator to show approximatevalve fast opening positions.

3. A device of the class described for remotely controlling amotor-operated valve, comprising the combination of means connected withsaid valve operating motor for starting and stopping the motor,selectively settable means including a multiple contact switch having abank of contacts for actuating said starting and stopping means andconnected to said starting means by only two lines, and indicating meansactuable by another bank of contacts to synchronously turn saidindicating means with said valve motor to indicate the approximateposition of said valve, said indicating means including a first electricmotor for moving an indicator to show approximate valve closingpositions and a second electric motor for moving said indicator to showapproximate valve slow opening positions and a third electric motor formoving said indicator to show approximate valve fast opening positions,said indicator and each of said electric motors being connected with acommon shaft.

4. Apparatus as claimed in claim 1 wherein means are provided forconnecting said motor to a power source, and said first relay has aclosed contact in series with said motor and said connecting means tocomplete the connection of said motor to said connecting means foroperating said motor to close a valve when no signal is impressed onsaid relays.

5. Apparatus for remotely controlling first and second electric motorsfrom a central location comprising the combination with a direct currentsource of voltage having first and second voltages of different values,of first, second and third relays, a multiple contact switch at saidcentral location for applying said voltages to said indicating meanswith said valve motor relays in different combinations, a firstrectifier operatively between said first and said second relays and asecond rectifier and impedance in series around said first rectifier andsaid second relay for conducting current in an opposite sense to correctpassing through said first rectifier and said second relay, said firstrelay being adapted to start said first motor on the application of afirst voltage combination, said second relay being adapted to transfercontrol of said first and second motors to local control upon theapplication of a different voltage combination, and said third relaybeing adapted to control said second motor upon the application ofanother voltage combination and also to transfer control of said firstand. second motor to local control.

6. Apparatus for controlling a vacuum pump motor and a steam valve motorof a heating system from a remote location comprising the combinationwith a direct current source of voltage having a first voltage and asecond voltage difierent in value from said first voltage, of multiplecontact switch means connected with said current source and providing atan output side of said switch means a plurality of combinations ofdifferent voltages at different values and polarities, a plurality ofrelays, two control lines electrically connecting said switch means withsaid relays said vacuum pump motor and said steam valve motor, saidrelays selectively controlling said motors in response to differentvoltage combinations selectively set at the output side of said switchmeans, said plurality of relays comprising two unidirectional lowvoltage relays connected in series and in opposition to one another, twounidirectional high voltage relays connected in series and in oppositionto one another, said series low voltage relays and said series highvoltage relays being connected in parallel forming a four-sided bridgecircuit with low voltage relays and high voltage relays conductingcurrent in the same direction being on opposite legs of the bridge, abi-directional diagonal low voltage relay connected at one end betweensaid low voltage relays and at the other end between said high voltagerelays to pass current in both directions depending on the polarity ofthe impressed signal, said relays responding in difierent combinationsdepending on the polarity and magnitude of the voltage selected.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 767,492 McCaughey Aug. 16, 1904 843,746 Hall Feb. 12, 19071,614,192 Ewald Jan. 11, 1927 1,704,736 Geiger Mar. 12, 1929 1,868,523De Flores July 26, 1932 1,944,326 Hudson Jan. 23, 1934 1,988,841 Haywardet a1. Jan. 22, 1935 2,216,102 Scherbak Sept. 24, 1940 2,321,699 OBrienJune 15, 1943 2,347,523 Suksdorf Apr. 25, 1944 2,363,061 Harrington Nov.21, 1944 2,368,937 McGillin et al. Feb. 6, 1945 2,384,167 Harrington etal. Sept. 4, 1945 2,389,204 Ludi et al. Nov. 20, 1945 2,512,639 GohorelJune 27, 1950 2,559,339 Blease et al. July 3. 1951 FOREIGN PATENTSNumber Country Date 314,112 Great Britain June 24, 1929

